The present invention relates to an electronic computer with equipment for debugging of the operative programs compiled by the operator before they are used.
Normally, in processors of high computing and storage capacity there are test or debugging programs already compiled and adapted to provide the operator with all the facilities which will enable him to follow the working out of the program under test and to obtain a visual display of any errors there may be.
It is obvious that since these debugging programs act on the programs being tested they must exist side by side with the latter in the memory of the processor. For this reason only processors of large dimensions offer these facilities.
Moreover, in the case of processors of small dimensions, the capacity of the memory is dimensioned to contain the program of maximum size from among those appertaining to the specific application of the processor (for example, application to accounting problems). Thus it is not possible for the programmer to test the compiled program, there being no available memory space. In fact, the makers of such processors tend to supply the necessary programs to the user already perfected or debugged.
This tendency finds its justification in the fact that an enlargement of the memory for the purpose of accomodating the debugging programs would affect the cost of the processor in a negative manner. Moreover, the user would acquire a processor with a low efficiency because of the unutilized portion of the memory.
The obvious disadvantage for the user deriving from this tendency is the absolute lack of flexibility of the processor purchased, inasmuch as the user is unable to personally make the slightest modification in the programs supplied with the processor.
This rigidity of performance of the processor puts the user in the position of depending entirely on the supplier of the processor for any development of service linked to a change of program.
Consequently, the user is compelled to request the supplier to modify the programs, a matter which involves long waiting times and high costs. In order to obviate these disadvantages, the user is prompted to modify the programs by himself and to ask outside computing centers for debugging of the modifications made. Even in this case, the user is forced to endure long waiting times and incur additional costs.
It is known however a minicomputer having an apparatus for debugging operative programs. This apparatus comprises a debugging panel not operable by the operator but only by the programmer. This panel includes a switch for switching the operation of the minicomputer from the normal mode to the debugging mode. There are provided also a group of switches each associated to a particular debugging operation, as displaying work memory register writing into the memory, step-by-step resuming etc.
In addition to this panel there is another panel for entering data and addresses into the memory which include also a display for displaying only two memory 8-bit bytes on binary code.
This debugging apparatus basically has two disadvantages, the first of which is of requiring specific devices and only in debugging mode and not used during the normal mode.
Such specific devices increase the cost of the debugging apparatus which therefore is expensive. The second disadvantage of such apparatus is of having a display which displays only two bytes at time.
Whereby it is difficult for the programmer to have a complete displaying of the desired memory register.
In consideration of the fact that the two modes of operations normal and debugging are mutually exclusive, there is therefore the technical problem of having a debugging equipment which utilizes the input-output devices as the keyboard, the console, the display and M.C. reader which normally equip the computer.